One day, PTA president Rena Fukii receives a complaint from a student's mother about the student council's immoral behavior. Desperate to stop their misconduct and have them expelled, she pleads with the school staff for help—only to be ensnared by the cunning student council members and forced into humiliating situations. With visible tan lines marking her body, the PTA president gradually falls victim to the students' malicious schemes, drawn deeper into their conspiracy and facing unexpected developments along the way.